Today around 2,745,000 flower gifts will be received, 37 million dinner dates will be enjoyed or endured, and the number of text messages will soar by 11 million. In Indonesia, sales of chocolates will double and in the United States there are expected to be 220,000 proposals of marriage - ten percent of the annual total.

But while the traditional Valentine's Day diamond ring may delight some, the ingenious maths behind modern matchmaking is even more dazzling.

Dating websites are booming in the UK. Six million Britons visit them each year, and in 2013, a studyThe study conducted two tests on 50 students. At the beginning of the experiment, half were given a cup of tea, and half a glass of water. The groups were then given creative challenges, like coming up with a "cool" name for a noodle restaurant. reported that more than a third of people who married in the US between 2005 and 2012 met their partner online. Perhaps surprisingly, the key to the success of online dating lies in clever calculations.

Dating sites rely on algorithms: sets of instructions which inform a machine what to do with certain information. Online dating sites ask users questions about their habits, beliefs and lifestyle choices and the computer runs the answers to find possible suitors.

At one site, OkCupid, users are given a numerical value for the answer they pick to questions such as 'how important is it that your potential partner is organised?' The processor then calculates how well a user scores against another's search criteria. But it gets more sophisticated: the algorithm can tell if a user's preferences are not fully frank: for example, if someone says they don't want to date people with dark hair but checks out their profiles anyway, the site will suggest some brunettes.

Algorithms are also behind the mobile phone app, TinderAs of 2021, dating app Tinder had recorded 65 billion matches worldwide. , which makes matches based on people's Facebook pictures.

But the lasting value of online dating has been disputed. A 2012 study by researchers in the United States concluded that no algorithm could predict an enduring partnership. The study concluded that dating sites 'are in a poor position to know how two partners will grow and mature over time.'

It is heartwarming to know that love can be explained by a formula, say some. Studies suggest that people who meet online are slightly less likely to divorce and they claim to be happier in their marriages - proof that maths can result in true love. Besides, online dating is essential for those with busy lives and limited opportunities to meet a mate.

What rubbish, retort the romantics. Maths is cold, impersonal and abstract, whereas true love is emotional, messy and unpredictable. While these algorithms might increase the probability of introducing people with similar interests, they cannot reproduce the magic of attraction. No one can ever fully understand the mysteries of love, so how can a computer?